2018 Volume 7 Issue 3 Pages 236-243
Currently, there is a need for precise motion control of industrial machines. For precise motion, it is important to keep the motion robust against disturbances such as gravity or reaction force from the environment. Industrial machines include flexible components such as gears and couplings, and they are modeled as a resonant system. Models expressing resonant systems are classified into lumped-parameter model and distributed-parameter model. Conventionally, the control theory based on the lumped-parameter model has been widely researched because that model is easy to deal with. However, the position which a disturbance acts on is limited to the generator or the lumped inertia of the load in these methods. Therefore, there is a danger that the disturbance suppression performance may deteriorate in the case that a distributed disturbance acts on the load. Here, the distributed-parameter model considering the position which a disturbance acts on, is proposed based on the wave equation. Wave-based modeling can consider the spatial dynamics of a disturbance. As a result, conventional disturbance suppression control is extended for the spatial dynamics.